/*

   Derby - Class org.apache.derby.impl.drda.EbcdicCcsidManager

   Copyright 2001, 2004 The Apache Software Foundation or its licensors, as applicable.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

 */

package org.apache.derby.impl.drda;

/**
 * A concrete implementation of a CcsidMgr used to convert
 * between Java UCS2 and Ebcdic as needed to handle character
 * DDM Parameters.  This implementation only supports converting
 * from the ASCII invariant of UNICODE to Ebcdic.  This should
 * be fine since this class is intended for converting
 * DDM Parameter data only.
 */
public class EbcdicCcsidManager extends CcsidManager
{
	private static final int[] conversionArrayToEbcdic = {
		0x0000,0x0001,0x0002,0x0003,0x0037,0x002d,0x002e,0x002f
		,0x0016,0x0005,0x0025,0x000b,0x000c,0x000d,0x000e,0x000f
		,0x0010,0x0011,0x0012,0x0013,0x003c,0x003d,0x0032,0x0026
		,0x0018,0x0019,0x003f,0x0027,0x001c,0x001d,0x001e,0x001f
		,0x0040,0x004f,0x007f,0x007b,0x005b,0x006c,0x0050,0x007d
		,0x004d,0x005d,0x005c,0x004e,0x006b,0x0060,0x004b,0x0061
		,0x00f0,0x00f1,0x00f2,0x00f3,0x00f4,0x00f5,0x00f6,0x00f7
		,0x00f8,0x00f9,0x007a,0x005e,0x004c,0x007e,0x006e,0x006f
		,0x007c,0x00c1,0x00c2,0x00c3,0x00c4,0x00c5,0x00c6,0x00c7
		,0x00c8,0x00c9,0x00d1,0x00d2,0x00d3,0x00d4,0x00d5,0x00d6
		,0x00d7,0x00d8,0x00d9,0x00e2,0x00e3,0x00e4,0x00e5,0x00e6
		,0x00e7,0x00e8,0x00e9,0x004a,0x00e0,0x005a,0x005f,0x006d
		,0x0079,0x0081,0x0082,0x0083,0x0084,0x0085,0x0086,0x0087
		,0x0088,0x0089,0x0091,0x0092,0x0093,0x0094,0x0095,0x0096
		,0x0097,0x0098,0x0099,0x00a2,0x00a3,0x00a4,0x00a5,0x00a6
		,0x00a7,0x00a8,0x00a9,0x00c0,0x00bb,0x00d0,0x00a1,0x0007
		,0x0020,0x0021,0x0022,0x0023,0x0024,0x0015,0x0006,0x0017
		,0x0028,0x0029,0x002a,0x002b,0x002c,0x0009,0x000a,0x001b
		,0x0030,0x0031,0x001a,0x0033,0x0034,0x0035,0x0036,0x0008
		,0x0038,0x0039,0x003a,0x003b,0x0004,0x0014,0x003e,0x00ff
		,0x0041,0x00aa,0x00b0,0x00b1,0x009f,0x00b2,0x006a,0x00b5
		,0x00bd,0x00b4,0x009a,0x008a,0x00ba,0x00ca,0x00af,0x00bc
		,0x0090,0x008f,0x00ea,0x00fa,0x00be,0x00a0,0x00b6,0x00b3
		,0x009d,0x00da,0x009b,0x008b,0x00b7,0x00b8,0x00b9,0x00ab
		,0x0064,0x0065,0x0062,0x0066,0x0063,0x0067,0x009e,0x0068
		,0x0074,0x0071,0x0072,0x0073,0x0078,0x0075,0x0076,0x0077
		,0x00ac,0x0069,0x00ed,0x00ee,0x00eb,0x00ef,0x00ec,0x00bf
		,0x0080,0x00fd,0x00fe,0x00fb,0x00fc,0x00ad,0x00ae,0x0059
		,0x0044,0x0045,0x0042,0x0046,0x0043,0x0047,0x009c,0x0048
		,0x0054,0x0051,0x0052,0x0053,0x0058,0x0055,0x0056,0x0057
		,0x008c,0x0049,0x00cd,0x00ce,0x00cb,0x00cf,0x00cc,0x00e1
		,0x0070,0x00dd,0x00de,0x00db,0x00dc,0x008d,0x008e,0x00df
	};

	private static final int[] conversionArrayToUCS2 = {
		0x0000,0x0001,0x0002,0x0003,0x009C,0x0009,0x0086,0x007F
		,0x0097,0x008D,0x008E,0x000B,0x000C,0x000D,0x000E,0x000F
		,0x0010,0x0011,0x0012,0x0013,0x009D,0x0085,0x0008,0x0087
		,0x0018,0x0019,0x0092,0x008F,0x001C,0x001D,0x001E,0x001F
		,0x0080,0x0081,0x0082,0x0083,0x0084,0x000A,0x0017,0x001B
		,0x0088,0x0089,0x008A,0x008B,0x008C,0x0005,0x0006,0x0007
		,0x0090,0x0091,0x0016,0x0093,0x0094,0x0095,0x0096,0x0004
		,0x0098,0x0099,0x009A,0x009B,0x0014,0x0015,0x009E,0x001A
		,0x0020,0x00A0,0x00E2,0x00E4,0x00E0,0x00E1,0x00E3,0x00E5
		,0x00E7,0x00F1,0x005B,0x002E,0x003C,0x0028,0x002B,0x0021
		,0x0026,0x00E9,0x00EA,0x00EB,0x00E8,0x00ED,0x00EE,0x00EF
		,0x00EC,0x00DF,0x005D,0x0024,0x002A,0x0029,0x003B,0x005E
		,0x002D,0x002F,0x00C2,0x00C4,0x00C0,0x00C1,0x00C3,0x00C5
		,0x00C7,0x00D1,0x00A6,0x002C,0x0025,0x005F,0x003E,0x003F
		,0x00F8,0x00C9,0x00CA,0x00CB,0x00C8,0x00CD,0x00CE,0x00CF
		,0x00CC,0x0060,0x003A,0x0023,0x0040,0x0027,0x003D,0x0022
		,0x00D8,0x0061,0x0062,0x0063,0x0064,0x0065,0x0066,0x0067
		,0x0068,0x0069,0x00AB,0x00BB,0x00F0,0x00FD,0x00FE,0x00B1
		,0x00B0,0x006A,0x006B,0x006C,0x006D,0x006E,0x006F,0x0070
		,0x0071,0x0072,0x00AA,0x00BA,0x00E6,0x00B8,0x00C6,0x00A4
		,0x00B5,0x007E,0x0073,0x0074,0x0075,0x0076,0x0077,0x0078
		,0x0079,0x007A,0x00A1,0x00BF,0x00D0,0x00DD,0x00DE,0x00AE
		,0x00A2,0x00A3,0x00A5,0x00B7,0x00A9,0x00A7,0x00B6,0x00BC
		,0x00BD,0x00BE,0x00AC,0x007C,0x00AF,0x00A8,0x00B4,0x00D7
		,0x007B,0x0041,0x0042,0x0043,0x0044,0x0045,0x0046,0x0047
		,0x0048,0x0049,0x00AD,0x00F4,0x00F6,0x00F2,0x00F3,0x00F5
		,0x007D,0x004A,0x004B,0x004C,0x004D,0x004E,0x004F,0x0050
		,0x0051,0x0052,0x00B9,0x00FB,0x00FC,0x00F9,0x00FA,0x00FF
		,0x005C,0x00F7,0x0053,0x0054,0x0055,0x0056,0x0057,0x0058
		,0x0059,0x005A,0x00B2,0x00D4,0x00D6,0x00D2,0x00D3,0x00D5
		,0x0030,0x0031,0x0032,0x0033,0x0034,0x0035,0x0036,0x0037
		,0x0038,0x0039,0x00B3,0x00DB,0x00DC,0x00D9,0x00DA,0x009F
	};

	EbcdicCcsidManager ()
	{
		super ((byte) 0x40, // 0x40 is the ebcdic space character
		       (byte) 0x4B,
		       new byte[] {
		//      '0',       '1',      '2',        '3',      '4',
		  (byte)0xf0,(byte)0xf1,(byte)0xf2,(byte)0xf3,(byte)0xf4,
		//      '5',       '6',       '7',       '8',      '9',
		  (byte)0xf5,(byte)0xf6,(byte)0xf7,(byte)0xf8,(byte)0xf9,
		//      'A',       'B',       'C',       'D',      'E',
		  (byte)0xc1,(byte)0xc2,(byte)0xc3,(byte)0xc4,(byte)0xc5,
		//      'F',       'G',       'H',      'I',       'J',
	  	  (byte)0xc6,(byte)0xc7,(byte)0xc8,(byte)0xc9,(byte)0xd1,
		//     'K',        'L',       'M',       'N',      'O',
		  (byte)0xd2,(byte)0xd3,(byte)0xd4,(byte)0xd5,(byte)0xd6,
		//     'P'
		  (byte)0xd7
		}
	  );
	}

	byte[] convertFromUCS2 (String sourceString)
	{
		byte[] bytes = new byte[sourceString.length()];
		convertFromUCS2 (sourceString, bytes, 0);
		return bytes;
	}

	int convertFromUCS2 (String sourceString,
		       byte[] buffer,
		       int offset)
	{
		for (int i=0; i < sourceString.length(); i++) {
			char c = sourceString.charAt (i);
			if (c > 0xff)
				buffer[offset++] = (byte) 63; // what's this ???
			else
				buffer[offset++] = (byte) (conversionArrayToEbcdic [c]); ;
		}

		return offset;
	}

	String convertToUCS2 (byte[] sourceBytes)
	{
		int i = 0;
		char[] theChars = new char[sourceBytes.length];
		int num = 0;

		for (i=0; i < sourceBytes.length; i++) {
			num = (sourceBytes[i] < 0) ? (sourceBytes[i] + 256) : sourceBytes[i];
			theChars[i] = (char) conversionArrayToUCS2[num];
		}

		return new String (theChars);
	}

	String convertToUCS2 (byte[] sourceBytes, int offset, int numToConvert)
	{
		int i = 0,j = 0;
		char[] theChars = new char[numToConvert];
		int num = 0;

		for (i = offset; i < (offset + numToConvert); i++) {
			num = (sourceBytes[i] < 0 ) ? (sourceBytes[i] + 256) : sourceBytes[i];
			theChars[j] = (char) conversionArrayToUCS2[num];
			j++;
		}
		return new String (theChars);
	}

}
